﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace Proxy
{
    public partial class main : Form
    {
        public main()
        {
            InitializeComponent();
        }

        public struct Struct_INTERNET_PROXY_INFO
        {
            public int dwAccessType;
            public IntPtr proxy;
            public IntPtr proxyBypass;
        };
        [DllImport("wininet.dll", SetLastError = true)]
        private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int lpdwBufferLength);

        private void RefreshIESettings(string strProxy)
        {
            const int INTERNET_OPTION_PROXY = 38;
            const int INTERNET_OPEN_TYPE_PROXY = 3;

            Struct_INTERNET_PROXY_INFO struct_IPI;

            // Filling in structure 
            struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY;
            struct_IPI.proxy = Marshal.StringToHGlobalAnsi(strProxy);
            struct_IPI.proxyBypass = Marshal.StringToHGlobalAnsi("local");

            // Allocating memory 
            IntPtr intptrStruct = Marshal.AllocCoTaskMem(Marshal.SizeOf(struct_IPI));

            // Converting structure to IntPtr 
            Marshal.StructureToPtr(struct_IPI, intptrStruct, true);

            bool iReturn = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_PROXY, intptrStruct, Marshal.SizeOf(struct_IPI));
        }

        private void SomeFunc()
        {
            RefreshIESettings("172.16.19.36:8800");

            System.Object nullObject = 0;
            string strTemp = String.Empty;
            System.Object nullObjStr = strTemp;
            myweb.Navigate("http://www.facebook.com");
        }

    }
}
